Washington
— It's Washington's hottest guessing game: Who will Michael Dukakis pick for vice-president on the Democratic ticket? Governor Dukakis, as tight-lipped as a New England clam, offers few hints. But insiders say his search for a compatible running mate centers on Capitol Hill.

Three senators getting close scrutiny appear to be John Glenn of Ohio, Bob Graham of Florida, and Lloyd Bentsen of Texas.

Two other solons - Sam Nunn of Georgia and Bill Bradley of New Jersey - have taken themselves out of the running.

Within that context, however, are a wide range of considerations, including regional balance, Washington experience, foreign policy expertise, and personal compatibility.

Any of those factors could weigh heavily in the final decision.

Political veteran Richard Scammon says the first political axiom when picking vice-presidents is, ``Do no harm.''

Experts recall earlier choices who have been a drag on the ticket. Thomas Eagleton, whose medical records came under scrutiny, was forced to withdraw from George McGovern's ticket in 1972. Geraldine Ferraro, the first woman nominee of a major party, hurt Democratic chances in 1984 when questions arose about her husband's finances.

Dukakis's search for a vice-president has ranged from Jesse Jackson on the left - whom the Massachusetts governor was to host for July 4th activities - to Senator Nunn on the right. More than two dozen names have floated in the news media during the past few weeks. But the hunt seems to be narrowing.

In addition to Senators Glenn, Graham, and Bentsen, Capitol Hill sources mention three congressmen - Thomas Foley of Washington, Lee Hamilton of Indiana, and Richard Gephardt of Missouri - as possibilities. But as Mr. Scammon says:

One Senate source is equally blunt: ``Anyone who tells you he knows who is on the short list is shooting you a line.''

While the choice of vice-president is dismissed by some as unimportant - ``I don't think the vice-president matters one bit,'' says Brookings Institution scholar John Chubb - others disagree.

The choice of a running mate is the first major act of a presidential nominee. It can unify the party, or cause serious schisms. It sends a signal to the nation about the nominee's willingness to reach out to all parts of the country, as when John Kennedy selected a Southerner, Lyndon Johnson, to run beside him.

Conventional wisdom says that in making his choice, Dukakis must give considerable weight to regional balance.

The governor's Northeast, urban, Harvard roots - much like those of Kennedy - call for a counterpart who can talk the language of small-town America.

Beyond that, Dukakis must consider the Electoral College: which region, along with the Northeast, can provide the state-by-state margins that he needs to put together at least 270 electoral votes?

Experts provide this region-by-region outlook: The South

Once the Democratic backbone, the South now leans Republican in presidential years.

Dukakis cannot afford to concede the entire South to George Bush. He must pick off at least a few states, such as Tennessee, Arkansas, and Kentucky, to be competitive nationwide.

Many Democrats argue that Dukakis should go with a ``Kennedy strategy,'' linking up with a Southerner, like Bentsen, to reverse Democratic fortunes there.

But Graham and Bentsen have an edge, because they come from large states with plenty of electoral votes.

Regional outlook: Graham ahead. The West

Pollsters like the West for Dukakis because he looks so strong in California, Oregon, and Washington. Some look for a Democratic breakthrough, too, in Colorado, New Mexico, and Nevada.

But there is a shortage of potential Democratic VPs, especially from California. Congressman Foley of Washington State, often mentioned, would probably help very little in California, which is a ``must win'' for Dukakis.

Other Western names: former Gov. Bruce Babbitt of Arizona and Rep. Patricia Schroeder of Colorado.

Regional outlook: Foley ahead. The Midwest

Despite the importance of the South and West, Dukakis may lean toward a Midwestern VP to shore up his strength in the industrial states.

Dukakis, who ran well in the South and West during the spring campaign, was unimpressive in the Illinois primary and the Michigan caucuses.

John Glenn, the Ohio folk hero, might help. Although Senator Glenn's presidential campaign fizzled on the launch pad in 1984, he is well known and squeaky clean. His military-astronaut image could also help Dukakis in the conservative South.

Other Midwesterners who could get the nod: Gov. James Blanchard of Michigan, Congressman Gephardt, Sen. Paul Simon of Illinois, Congressman Hamilton (who chaired the House committee that investigated the Iran-contra affair), and the Rev. Mr. Jackson, who hails from Illinois.

Regional outlook: Glenn ahead. The East

Although Dukakis comes from Massachusetts, he has toyed with selecting someone from the same region of the country. Senator Bradley was approached at one point. Rep. William Gray III of Pennsylvania is sometimes mentioned. And what about Gov. Mario Cuomo of New York?